Alleopathic (releases herbicide to kill all others plants near it) Seeds and creeping rhizomes are used for reproduction. Toxic to horses. Bracts can have fine hairs,egg shape, and a papery margin which help you distinguish this from spotted knapweed. Russian Knapweed is distinguishable from spotted knapweed by is black roots that are 8 or more feet long and go deep. Russian Knapweed has a distinguishably different leaf than Diffused Knapweed.Diffuse Knapweed Russian Knapweed has smooth papery bracts that lack spines. Russian Knapweed shoot and leaves and have a rosette emergance in the spring. Watch this video for more information http://www.youtube.com/watch?v=rRWj9ftK85c
Control
Hand pulling difficult and ineffective Deep plowing is fairly effective Mowing very ineffective Burning ineffective Chemical- 2,4D dicambia, plicoram, clopyralid Research for your specific area Biological- Subanguina picridis a nematode that kills the Russian Knapweed Grazing animals is severly discouraged due to the fact that the knapweed is toxic to horses and it is not a good control method.
Russian Knapweed
(Acroptilon Repense)
Perennial (lives 3 or more years).
Interesting Facts
Alleopathic (releases herbicide to kill all others plants near it)Seeds and creeping rhizomes are used for reproduction.
Toxic to horses.
Bracts can have fine hairs,egg shape, and a papery margin which help you distinguish this from spotted knapweed.
Russian Knapweed is distinguishable from spotted knapweed by is black roots that are 8 or more feet long and go deep.
Russian Knapweed has a distinguishably different leaf than Diffused Knapweed.Diffuse Knapweed
Russian Knapweed has smooth papery bracts that lack spines. Russian Knapweed shoot and leaves and have a rosette emergance in the spring.
Watch this video for more information http://www.youtube.com/watch?v=rRWj9ftK85c
Control
Hand pulling difficult and ineffectiveDeep plowing is fairly effective
Mowing very ineffective
Burning ineffective
Chemical- 2,4D dicambia, plicoram, clopyralid
Research for your specific area
Biological- Subanguina picridis a nematode that kills the Russian Knapweed
Grazing animals is severly discouraged due to the fact that the knapweed is toxic to horses and it is not a good control method.
Impacts
crowds out the native speciestakes over feilds
Sources
http://www.agdepartment.com/NoxiousWeeds/pdf/RUSSIANKNAPWEED.pdfhttp://www.ext.colostate.edu/pubs/natres/03111.html
Colorado Weed Management Association Flash Cards
Parker, Robert. Weeds of the West. [S.l.]: Diane Pub., 1998. Print